PURPOSE: A cosmetic comosition and a pharmaceutical composition containing phenolic compounds isolated from Dendropanax morbifera extract are provided to effectively suppress melanogenesis and to enhance skin whitening. CONSTITUTION: A cosmetic composition for skin whitening contains glycopyranoside-based polyether phenol compounds and pharmaceutically acceptable salt thereof as an active ingredient. An external use skin composition with a function of skin whitening contains glycopyranoside-based polyether phenol compounds and pharmaceutically acceptable salt thereof as an active ingredient. The phenolic compound is (+)-syringaresinol-O-B-D-glucopyranoside. The cosmetic composition is skin lotion, skin toner, astringent, milk lotion, moisture lotion, massage cream, nutrition cream, moisture cream, hand cream, essence, pack, soap, cleansing foam, cleansing lotion, cleansing cream, body lotion, or body cleanser. The pharmaceutical composition is manufactured in the form of a cream, gel, patch, spray, ointment, limiment, paster, and cataplasma.본 발명은 황칠나무 추출물로부터 분리된 페놀성 화합물 및 이의 약학적으로 허용가능한 염을 유효성분으로 함유하는 피부미백용 화장료 조성물 및 피부외용 약제 조성물을 제공하기 위한 것이다.